Abstract
INTRODUCTION: The measles outbreak registered in Brazil in 2018, forced the alteration of preventive actions for the disease, leading to the addition of the zero dose of the Triple Viral vaccine for children from 6 months of age to 11 months and 29 days. The zero dose precedes the first dose, but does not exclude its mandatory nature. Studies that address the harms and benefits of the extra early dose are scarce. This study aimed to point out the pros and cons of zero dose management in light of the report of an adverse hypersensitivity reaction to this dose of the Triple Viral vaccine. CASE REPORT: Male patient, 6 months old, attended the childcare consultation to investigate a possible hypersensitivity reaction after administration of the zero dose of the Triple Viral vaccine. On physical examination, he showed good general condition, development compatible with age and generalized hypersensitivity. DISCUSSION: It addresses the importance of the Triple Viral Vaccine and raises the question of few studies about the consequences of the new vaccine protocol, which recommends the administration of zero dose in children under one year old, in the face of the measles outbreak. CONCLUSION: The Triple Viral vaccine is an efficient mechanism to fight measles. The benefits outweigh the adverse effects of the vaccine, however, further studies are needed in order to understand the real consequences of administering the zero dose to children under one year of age.